End effector with redundant closing mechanisms

Abstract

End effectors with redundant closing mechanisms, and related tools and methods are disclosed. The disclosed end effectors may be particularly beneficial when used for minimally invasive surgery. An example surgical tool comprises an elongate shaft having a proximal end and a distal end, a tool body disposed at the distal end of the shaft, a jaw movable relative to the tool body between a clamped configuration and an open configuration, a first actuation mechanism coupled with the jaw and operable to vary the position of the jaw relative to the tool body between the clamped configuration and the open configuration, and a second actuation mechanism coupled with the jaw. The second actuation mechanism has a first configuration where the jaw is held in the clamped configuration and a second configuration where the position of the jaw relative to the tool body is unconstrained by the second actuation mechanism.

What is claimed is: 
     
       1. A surgical tool comprising:
 an elongate shaft having a proximal end and a distal end; 
 a tool body disposed at the distal end of the shaft; 
 a jaw movable relative to the tool body between a clamped configuration and an open configuration; 
 a first actuation mechanism coupled with the jaw and operable to vary the position of the jaw relative to the tool body between the clamped configuration and the open configuration; and 
 a second actuation mechanism coupled with the jaw, the second actuation mechanism having a first configuration in which the jaw is held in the clamped configuration and a second configuration in which the position of the jaw relative to the tool body is unconstrained by the second actuation mechanism; 
 wherein the jaw opens and closes on a distal side of a jaw pivot, wherein the first actuation mechanism applies force to the jaw at a proximal side of the jaw pivot to vary position of the jaw, and wherein the second actuation mechanism applies force to the jaw at the proximal side of the jaw pivot to hold the jaw in the clamped configuration. 
 
     
     
       2. The tool of  claim 1 , wherein the first actuation mechanism is back-drivable. 
     
     
       3. The tool of  claim 1 , wherein the first actuation mechanism comprises cables. 
     
     
       4. The tool of  claim 3 , wherein:
 a pulling movement of a first cable segment of the first actuation mechanism moves the jaw towards the open configuration; and 
 a pulling movement of a second cable segment of the first actuation mechanism moves the jaw towards the clamped configuration. 
 
     
     
       5. The tool of  claim 4 , wherein the first actuation mechanism further comprises:
 a first linkage coupling the first cable segment with the jaw and the tool body; and 
 a second linkage coupling the second cable segment with the jaw and the tool body. 
 
     
     
       6. The tool of  claim 1 , wherein the second actuation mechanism is non-back-drivable. 
     
     
       7. The tool of  claim 1 , wherein the second actuation mechanism is operable to produce a clamping force between the jaw and the tool body of at least 20 lbs. 
     
     
       8. The tool of  claim 1 , wherein the second actuation mechanism comprises a leadscrew. 
     
     
       9. The tool of  claim 8 , wherein:
 the second actuation mechanism further comprises a leadscrew driven cam operatively coupled with the leadscrew; and 
 the jaw comprises an interfacing cam surface for contact with the leadscrew driven cam. 
 
     
     
       10. The tool of  claim 1 , further comprising an actuated device coupled to the jaw. 
     
     
       11. A tool for mounting on a manipulator having a first drive, the tool comprising:
 a proximal tool chassis releasably mountable to the manipulator; 
 a drive motor coupled with the tool chassis and disposed adjacent the tool chassis; 
 a distal end effector comprising a movable jaw; 
 an instrument shaft having a proximal end adjacent the chassis, and a distal end adjacent the end effector; 
 a first actuation mechanism coupling the first drive to the end effector when the chassis is mounted to the manipulator so as to articulate the end effector between an open configuration and a clamped configurations; and 
 a second actuation mechanism coupling the drive motor to the end effector so as to articulate the end effector into the clamped configuration from the open configuration; 
 wherein the moveable jaw opens and closes on a distal side of a jaw pivot, wherein the first actuation mechanism applies force to the jaw at a proximal side of the jaw pivot to vary position of the moveable jaw, and wherein the second actuation mechanism applies force to the moveable jaw at the proximal side of the jaw pivot to hold the moveable jaw in the clamped configuration. 
 
     
     
       12. The tool of  claim 11 , wherein the first actuation mechanism is back-drivable. 
     
     
       13. The tool of  claim 11 , wherein the first actuation mechanism comprises cables extending from the chassis distally within a bore of the instrument shaft operatively coupling the end effector to the first drive. 
     
     
       14. The tool of  claim 11 , wherein the second actuation mechanism is non-back-drivable. 
     
     
       15. The tool of  claim 11 , wherein the second actuation mechanism comprises a leadscrew driven cam. 
     
     
       16. The tool of  claim 11 , wherein the second actuation mechanism has a first configuration where the jaw is held in the clamped configuration and a second configuration where the position of the jaw relative to the tool body is unconstrained by the second actuation mechanism. 
     
     
       17. The tool of  claim 11 , wherein the second actuation mechanism comprises a drive shaft mounted for rotation within a bore of the instrument shaft and operatively coupling the end effector with the drive motor. 
     
     
       18. A surgical instrument comprising:
 an end effector comprising a movable jaw; 
 a first jaw actuation mechanism coupled to the movable jaw; and 
 a second jaw actuation mechanism coupled to the movable jaw; 
 wherein the first jaw actuation mechanism moves the movable jaw from an open position to a closed position independently of the second jaw actuation mechanism; 
 wherein the second jaw actuation mechanism moves the movable jaw from the open to the closed position independently of the first jaw actuation mechanism; and 
 wherein the moveable jaw opens and closes on a distal side of a jaw pivot, and wherein the first jaw actuation mechanism applies force to the moveable jaw at a proximal side of the jaw pivot to vary position of the moveable jaw, and wherein the second jaw actuation mechanism applies force to the moveable jaw at the proximal side of the jaw pivot to hold the moveable jaw in a clamped position. 
 
     
     
       19. The surgical instrument of  claim 18 , wherein the second jaw actuation mechanism in a first configuration holds the movable jaw in the clamped position that prevents the first jaw actuation mechanism from moving the movable jaw. 
     
     
       20. The surgical instrument of  claim 19 , wherein a maximum clamping force of the movable jaw provided by the second jaw actuation mechanism is larger than a maximum clamping force of the movable jaw provided by the first jaw actuation mechanism. 
     
     
       21. The surgical instrument of  claim 18 , wherein:
 a force used by the first jaw actuation mechanism to move the moveable jaw from the open to the closed position comprises a linear force; and 
 a force used by the second jaw actuation mechanism to move the moveable jaw from the open to the closed position comprises a torque. 
 
     
     
       22. The surgical instrument of  claim 18 , wherein:
 the first jaw actuation mechanism comprises a cable-driven mechanism; and 
 the second jaw actuation mechanism comprises a leadscrew-driven mechanism. 
 
     
     
       23. The tool of  claim 1 , wherein the second actuation mechanism applies force to the jaw at the proximal side of the jaw pivot to vary position of the jaw.